What is the best course of action for a patient with severe anemia (hemoglobin 7.2) and thrombocytosis (platelet count 625)?

Management of Severe Anemia with Reactive Thrombocytosis

This patient requires immediate blood transfusion for severe anemia (hemoglobin 7.2 g/dL) and investigation for iron deficiency as the likely cause of both the anemia and reactive thrombocytosis. 1

Immediate Transfusion Management

Transfuse packed red blood cells using a restrictive strategy with a threshold of 7 g/dL, targeting a post-transfusion hemoglobin of 7-9 g/dL. 2, 1

Transfusion Protocol:

• Administer one unit of packed RBCs at a time, then reassess clinical status and hemoglobin before giving additional units 2, 1
• Each unit should increase hemoglobin by approximately 1-1.5 g/dL 1
• If the patient has cardiovascular disease or acute coronary syndrome, consider a slightly higher threshold of 8 g/dL 2, 1
• If the patient is hemodynamically unstable, has active bleeding, or shows signs of end-organ ischemia (chest pain, altered mental status, tachycardia, hypotension), transfuse immediately regardless of the specific hemoglobin level 2, 1

Critical Assessment Before Transfusion:

• Evaluate for hemodynamic instability, tachycardia, orthostatic hypotension, or symptoms of inadequate oxygen delivery 2, 1
• Check for signs of acute coronary syndrome (ECG changes, chest pain) 1
• Assess volume status and risk factors for transfusion-associated circulatory overload 1

Investigation of Thrombocytosis

The platelet count of 625,000/µL represents reactive thrombocytosis, most likely secondary to iron deficiency anemia. 3, 4

Diagnostic Workup:

• Obtain iron studies immediately: serum iron, total iron binding capacity (TIBC), serum ferritin, and transferrin saturation 2
• Check reticulocyte count, lactate dehydrogenase (LDH), indirect bilirubin, and haptoglobin to evaluate for hemolysis 5
• Perform peripheral blood smear to assess red cell morphology (microcytic, hypochromic cells suggest iron deficiency) 5, 4
• Consider stool guaiac testing and evaluation for gastrointestinal blood loss 4

Understanding the Thrombocytosis:

• Reactive thrombocytosis occurs in approximately 32.6% of patients with iron deficiency anemia 3
• The thrombocytosis is typically benign and resolves with iron replacement 4
• However, patients with IDA and thrombocytosis have a 2-fold increased risk of thrombotic complications (15.8% vs 7.8% in IDA alone) 3
• Platelet count is strongly negatively correlated with hemoglobin level—as hemoglobin decreases, platelet count increases 3

Iron Replacement Strategy

If iron deficiency is confirmed (ferritin <800 ng/mL and transferrin saturation <20%), initiate iron replacement therapy. 2

Iron Supplementation Approach:

• Intravenous iron has superior efficacy and should be considered first-line, especially in severe anemia 2
• Oral iron is less effective but more commonly used; it is appropriate for mild cases or when IV access is limited 2
• The thrombocytosis will normalize with adequate iron replacement and does not require specific treatment 4

Functional Iron Deficiency:

• If ferritin is <800 ng/mL and transferrin saturation is <20%, this represents functional iron deficiency requiring supplementation 2
• If ferritin is >800 ng/mL or transferrin saturation is ≥20%, IV or oral iron supplementation is not needed 2

Monitoring and Follow-up

• Recheck hemoglobin after each unit of packed RBCs to guide further transfusion 1
• Monitor platelet count during iron replacement—expect normalization as anemia improves 3, 4
• Reduce diagnostic phlebotomy volume and frequency to prevent worsening anemia 2
• If anemia persists despite iron replacement, consider hematology consultation for alternative or complicating etiologies 2

Critical Pitfalls to Avoid

• Do not transfuse to hemoglobin >10 g/dL—liberal transfusion strategies increase complications without improving outcomes 2, 1
• Do not treat thrombocytosis with antiplatelet agents or anticoagulation unless there is a separate indication; reactive thrombocytosis from iron deficiency is benign and resolves with treatment of the underlying cause 4
• Do not overlook the increased thrombotic risk—while rare, patients with severe IDA and thrombocytosis can develop venous thromboembolism, including cerebral venous thrombosis 3, 6
• Do not assume the thrombocytosis is primary (essential thrombocythemia) without first ruling out reactive causes, particularly iron deficiency 3, 4
• Do not delay iron studies—obtaining these before transfusion provides the most accurate assessment of iron stores 2